Guys,

Shocking news; My DX7 (or the NiMH battery) has litteraly EXPLODED today! I was running a range test with the DX7 (luckily!) in a seperate room without people (or animals) around. When i got down the stairs, i already lost signal (100ft away) and heared an explosion... So rushing back up, the whole room is filled with smoke (how dangerous is NiMH smoke?!) and battery-parts are everywhere! One bit (the culprit cell i think) even dented the wall (stucko)!

The DX7's batterylid was still on, but melted and deformed, as the lowerpart of the back body... A great big black (charcoal like) mess all around... If i'd had it in my hands, i don't think i could have ever flown again...

So several question:
- Is there any liabiltiy on Spektrum's side?
- Best way to contact Spektrum (as they aren't represented here in NL)
- How dangerous are NiMH internals?

Damn, i'm still scared and shaking... Havent taken pictures of the mess, but will take pictures of the remainders (hopefully it'll still work...).

Pff, needed to get it out

Ummm WOW!!!

Wow! That sucks! [:@] How new is your DX7? I would definitely contact Spektrum. Did the fire damage ANYTHING in your house? I'm not sure how this process works in the Netherlands (my mom's maiden name is Meyer, BTW), but in the states, if there was damage to your house AT ALL (smoke, etc...) you would call your home insurance company. They wil send an investigator out to your house and make arrangements for repairs. The catch is that there is a certain amount of $$ (deductable) that the homeowner is required to pay no matter what. If I were you, I would find out about the insurance thing first, then contract Spektrum and the place you bought ti from. I would ask for a full replacement of the unit and payment of any fees caused by the device's failure.

This makes me paranoid about my own DX7's battery now.... [:-]

Holy smoke'n batteries. Even if the smoke is not harmful, still open all your windows (not matter the temp outside) and let it air out for a long while.

Yup, one cell of the NiMH (one cell, meaning one AA-type cell) was 10ft away, on the floor, after denting... The whole pack has blown itself through the melted batterylid and tray...

How long have you had the DX7?

I'm still airing out the upperlevel of the house... The smoke was in the room and hallway... It's not the damage to the wall (just a AA-battery shaped dent) i care about, it's the DX7 itself! Quite an expensive piece of equipment....

Its just several (4 i guess) months old... Still have the receipts and everything. Even the box with the original plastics and all!

jeez, shufflez - are you ok?

by the way, was it plugged in? - if it was, how long was it plugged in? - charger/plug-in power supply failure, sending pure line voltage into the unit?

could a dead short in the dx7 guts blow up a nimh like that?

i have a lipo and i charge it in the lipo sack, so no probs hat way i guess, but i can empathize cause my first cp stock radio burned up in my hands - shorted out in the throttle trim


edge

Spektrum does have a support forum here on RCU [link=http://www.rcuniverse.com/forum/forumid_116/tt.htm]found here[/link] and He may have an explanation for you. Thank God you are OK shufflez. Your great ideas and humorous wit would be sorely missed on here!
That really could be a liability for JR radios if there is a battery issue going on. How stunning is that development? How does one know if they are protected from what you experienced? I have a DX6 myself and really wonder about the batterys in mine now too.
Again, very glad to hear that you and yours are all OK.


__________________________________________________ ___________________________________


Of all the things I ever lost....................................... I miss my mind the most!

Yes, 'luckily' the misses is ill, so she was in bed and i was downstairs... But the frickin room is a major mess... The desk used to be white, but was covered in a thick layer of charcoal... Debree (?) all over the floor as well...

It wasn't plugged in, but it was fully charged. I charge it with a normal 1500mAh powersupply directly into the DX7. I've just checked it, the supply is still good.
Shouldn't be a problem right, as most of my devices charge with the battery inside! (Phones, PDA, GPS, Wii&Xbox controllers, etc)

Maybe if i had it in my hands, i'd feel it heat up and would have been able to remove the battery on time, saving my DX7...

Wowsers!
First, I'm really glad that you and the Mrs (Ms?) are OK. That could have been way worse than smoke and a dent.

I lost a Falcon 40 Tx due to a battery melt down just a couple of weeks ago. It was powered by eight 2600 mah NiMH AA cells. It was on a charger at the time. I thought that I had it on the 500 mah charger to top-off the charge, but I grabbed the wrong plug so it was on a 1.5 amp charger. And it was on the charger for too long, according to Mr. Obvious.

The cells generate heat as they reach full charge and the Tx had the back on it, so it was locked up pretty tight. One of the cells failed in some unknown manner and I think that started the whole mess. I don't know if the cells are exothermic or not - perhaps the failed cell generated enough heat to short the adjacent cell, and so through the pack. Four of the eight were melted beyond recognition. Anyhow, the case melted down into rather a mess. For me, it was a significant loss with Eight premium NiMH cells ($20), Charger wall power supply ($20), Tx ($40). That compared to your loss is nothing.
I was in the room when they went and I was able to get the mess outside as the cells and plastic melted into gooey globs.

You were range testing the Tx by leaving the Tx and carrying the heli or just a receiver of some kind? Forgive me if I sound ignorant, but I've not seen a range test done that way. I'm not being critical, just curious.

I'll bet you will have more luck with the manufacturer of the AA cells. Even if the Tx was to dead short the power of today's NiMH cells will burn a wire, blow a fuse or open a circuit before a cell explodes. I'll bet a cell shorted internally and started the whole mess.

I know you have been collecting funds for your heli and Tx for some time and they were a great source of pride to you. I'm really sorry to hear that the Tx is (likely) gone. Is it possible that the innards are OK but the case needs to be replaced? Does your home owner's insurance cover personal property? This was no less an accident than spilling a gallon of paint down a newly carpeted stariway (no, I didn't) and personal property includes toys, I beleive.

Good luck and keep us posted.
Soloboss

screw the dx7, more worried about your hands!!!

checking the net - it looks like the nimh batts in the dx7 are crap

http%3a//www.rcuniverse.com/forum/fb.asp%3fm=6405339
http%3a//www.runryder.com/helicopter/t381713p1/
http://www.helifreak.com/showthread.php?t=50841

lipo is looking safer lol

perhaps this is the nasty little secret behind the blade 400's delay?


edge

I recently got a lipo for my Futaba tx and love it.

from the comments going on the internet about the nimh dx7 batteries, i would heartily suggest that everybody with a dx7 get a lipo (any trex 450 lipo will work according to the net stuff above) instead of running the nimh batteries

shufflez, always paving the way for the rest of us


edge

possibly you pinched the wire at some point when installing the battery cover and the battery finally shifted into a position that allowed the wires to cross.

Only mention this cause my dx7 came with some insulation missing on the wires from a pinch at the factory.

scary - yet another bad dx7 nimh battery pack

i'm now thinking of putting mine outside in the flower pot with the busted lipo


edge

Nothing wrong with my battery, just a little missing insulation on the wires.
Shrink wrapped and all has ben good for months now

Shufflez,
Wasn't that dx7 supposed to be your Christmas present? Just imagine what your wife would of said if you burned down your house with a gift that you wern't suppose to be playing with yet [X(].
I did a little research and couldn't find much that would explain why the battery blew. When you have time open up the dx7 and see if you can find a hot (melted) spot.
Glad that everyones alright.

http://en.wikipedia.org/wiki/Ni-Mh

Shufflez--


Good to hear nobody got hurt. I can't even imagine to wonder what your hands would look like if you were holding that thing...Could've been much worse. Don't worry about the DX-7, you'll get another one. Who knows maybe Spektrum will send you two...Lol..


I've never had a problem with my 6 cell-Nimhs that I run in my RC cars. You now left me to be more aware...! One time I was changing out connectors on one of my Trinity 4200 racing packs (Nimh 6-cell), and I accidently barely touch the pos/neg together, and instantly the wires stuck together and within a couple seconds the wires were literally orange...Lol.. I tried to un-bind them, but they were melting together, luckily there was a screwdriver lying right there for a quick flick to seperate them. I was a second away from seriously throwing it out in the yard, and expect the worse...Lol.. Another time I Was running one of my stadium trucks with Novak's brushless set-ups and racing ecu that is very high powered with the same above batt, and after one of my runs, the Nimh batt was soooooo, hot, that when I went to grab it out of the chassis, the whole thing sagged down, as all the cells were literally "soft" or mushy. I had to lay it on a flat service to cool or it would have just cooled in an irregular state...I told my friend, I better put this outside...Lol..I haven't tried charging it since...It's been months. The car stuff now sits... Got into heli's...Lol..


Well, we all are going to be curious to see the outcome of what Spektrum has to say. I'am nervous enough flying my heli's, let alone worrying about my hands blowing up...! I saw the post right when I logged on, and thought "Yeah right, Shufflez is pulling are leg", but low and behold, I still can't believe it. I remember when you first got that thing ! I'am still in the "figuring out stage" with my Dx-7...lol..



Lookyj posted some good DX-7 lipo batts from Common Sense RC over in the Weeeee... thread one is a 2500mah, and they have now even a 2800mah http://www.commonsenserc.com/index.php?cPath=37_27 Some guys are getting a month on there TX time using lipo's...I'll upgrade in time, or when money starts falling from the sky....



You didn't modify it at all did you ? I know your an electronics buff, so had to ask. I could picture you diggin' around in the guts of the DX-7, trying to install some "Super Capacitor or something...lol..! Also, remember and we talked about this before, but you are part of the "COLLECTIVE"... So be careful, and take care of yourself....We need you..Remember, like the mafia....There is "no getting out"...LOL !




Have a good one,



-- Jeff

WOW, glad you are okay Shufflez!!! Didn't know there was a problem with the batteries in the DX7, from the post's above it appears your not the only one. Hmmm might have to re-think the whole tx thing all of a sudden Or run a lipo in it. Kind of scary. Sure hope Spektrum steps up to the plate for you.

I'm going back to rubber-band powered, balsa airplanes.

LOL....! Yeah right...Mark, your mind would get so bored I couldn't even begin to imagine...You could only "tinker" and be able to discover new logic only so much on a few pieces of wood and a fragment of rubber...Lol.. Shufflez needs to tell Spektrum that "The Boyz" over at RCU are curious on the DX-7 mishap...Lol.. You stay put with the coaxials and FP that ya like, as we still need ya here and all...


Alright, happy adventures....


-- Jeff

Hey, don't laugh. I'm back from the LHS and I have my first rubber band powered plane in 40 years. I wonder just how much I can get out of a stick and a rubber band.
And the big question remains - can I reconfigure an airplane into a free flight coaxial helicopter?

My budget took a dump this weekend. I was thinking seriously about going to the next level helicopter, but my Canon S1 IS died. It's internal and it's a heat problem - problems like that can easily cost more than the cost of the camera to repair. So I'm ordering a Canon S3 IS this evening.
I wish Michael sold digital cameras.

Soloboss

Shufflez,

Glad nobody got injured. You do need to pursue with the manufacture of the battery. You have smoke damage to your home and they may be liable for that. Not sure, you may want to talk to an attorney on that issue.

Soloboss,

LOL, I'm sure YOU would come up with a better RUBBER-BAND.



Thanks for this post Shufflez, makes us all more knowledgeble of the dangers of this hobby,

Dave / Choppersrule

Does a rubber band that is wound by a tiny motor still count?